Hydroxyurea for the Treatment of Patients With Sickle Cell Anemia
| Status: | Completed |
|---|---|
| Conditions: | Anemia, Anemia |
| Therapuetic Areas: | Hematology |
| Healthy: | No |
| Age Range: | 18 - Any |
| Updated: | 4/6/2019 |
| Start Date: | February 7, 1984 |
| End Date: | May 18, 2015 |
Effect of Hydroxyurea on Fetal Hemoglobin Synthesis in Patients With Sickle Cell Anemia
A total of fifty severely affected patients with homozygous sickle cell disease or other
sickling disorders (e.g. B negative or B positive Thalassemia/Sickle) who are greater than 18
years of age will be eligible for treatment. Such patients must be able to tolerate an
extensive period without blood transfusion and have relatively well preserved renal and
hepatic function (creatinine less than 1.5 mg/dl and normal liver function test with
exception of a mild elevation in transaminase). Evidence of severe sickle cell anemia will
include recurrent pain crisis, chronic bone oain, evidence of aseptic necrosis with symptoms,
and intractable leg ulcer, etc.
On admission to the study, each patient will receive a complete history and physical
examination. These data and standard laboratory evaluation, including a test for pregnancy if
appropriate, will be adequate to ascertain whether any of the criteria for exclusion are
present. Each patient must accept responsibility for for using an effective means of
contraception. Patients who are found to be HIV positive will be excluded from the study.
sickling disorders (e.g. B negative or B positive Thalassemia/Sickle) who are greater than 18
years of age will be eligible for treatment. Such patients must be able to tolerate an
extensive period without blood transfusion and have relatively well preserved renal and
hepatic function (creatinine less than 1.5 mg/dl and normal liver function test with
exception of a mild elevation in transaminase). Evidence of severe sickle cell anemia will
include recurrent pain crisis, chronic bone oain, evidence of aseptic necrosis with symptoms,
and intractable leg ulcer, etc.
On admission to the study, each patient will receive a complete history and physical
examination. These data and standard laboratory evaluation, including a test for pregnancy if
appropriate, will be adequate to ascertain whether any of the criteria for exclusion are
present. Each patient must accept responsibility for for using an effective means of
contraception. Patients who are found to be HIV positive will be excluded from the study.
Hydroxyurea is a cell-cycle specific agent that blocks DNA synthesis by inhibiting
ribonucleotide reductase, the enzyme that converts ribonucleotides to deoxyribonucleotides.
Hydroxyurea has been shown to induce the production of HbF, initially in non-human primates,
and now in more than fifty patients with sickle cell anemia. The majority of patients with
sickle cell disease respond to the drug with a more than two-fold increase in HbF levels; in
some patients the percent of HbF exceeds 10 or 15 percent. It is estimated that levels of 20
percent are required to substantially reduce the sickling propensity of red cells and to
modulate disease severity. We propose now to treat several patients chronically with
hydroxyurea to monitor the durability of the response, to examine for unanticipated long term
sided effects and to determine hematological changes occurring longitudinally. Such patients
will be candidates for protocols determining the ability of other agents to enhance HbF
synthesis, especially in hydroxyurea non-responders. Finally, a series of in vitro studies
are planned to attempt to develop predictors of response.
ribonucleotide reductase, the enzyme that converts ribonucleotides to deoxyribonucleotides.
Hydroxyurea has been shown to induce the production of HbF, initially in non-human primates,
and now in more than fifty patients with sickle cell anemia. The majority of patients with
sickle cell disease respond to the drug with a more than two-fold increase in HbF levels; in
some patients the percent of HbF exceeds 10 or 15 percent. It is estimated that levels of 20
percent are required to substantially reduce the sickling propensity of red cells and to
modulate disease severity. We propose now to treat several patients chronically with
hydroxyurea to monitor the durability of the response, to examine for unanticipated long term
sided effects and to determine hematological changes occurring longitudinally. Such patients
will be candidates for protocols determining the ability of other agents to enhance HbF
synthesis, especially in hydroxyurea non-responders. Finally, a series of in vitro studies
are planned to attempt to develop predictors of response.
- INCLUSION CRITERIA:
A total of fifty severely affected patients with homozygous sickle cell disease or other
sickling disorders (e.g., B negative or B positive Thalassemia/Sickle) who are greater than
18 years of age will be eligible for treatment. Such patients must be able to tolerate an
extensive period without blood transfusion and have relatively well preserved renal and
hepatic function (creatinine less than 1.5 mg/dl and normal liver function test with
exception of a mild elevation in transaminase). Evidence of severe sickle cell anemia will
include recurrent pain crisis, chronic bone pain, evidence of aseptic necrosis with
symptoms, and intractable leg ulcers, etc.
EXCLUSION CRITERIA:
Patients who are found to be HIV positive will be excluded from the study.
We found this trial at
1
site
9000 Rockville Pike
Bethesda, Maryland 20892
Bethesda, Maryland 20892
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